Abstract and keywords
Abstract (English):
The Irkutsk Incoherent Scatter Radar (IISR) allows us to carry out passive radio observations of the Sun and other powerful radio sources. We describe a method for absolute measurements of spectral flux density of solar radiation at IISR. The absolute measurements are meant to determine the flux density in physical units [W·m–2·Hz–1]. The IISR antenna is a horn with frequency beam steering, therefore radio sources can be observed at different frequencies. Also there is a polarization filter in the antenna aperture, which passes only single (horizontal) polarization. To acquire flux density absolute values, the IISR receiver is calibrated by the Cygnus-A radiation. Since the Sun’s position in the IISR antenna pattern is determined by a frequency differing from the Cygnus-A observation frequency, we perform an additional calibration of the frequency response in the 154–162 MHz operation frequency range, using the background sky noise. The solar disk size is comparable with the main beam width in the north—south direction, hence the need to take into account the shape of the brightness distribution in the operation frequency range. The average flux density of the quiet-Sun radiation was ~5 sfu (solar flux units, 10–22 W·m–2·Hz–1) at the 161 MHz frequency.

solar flux, absolute measurements, Irkutsk Incoherent Scatter Radar (IISR)
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1. Baars J. History of flux-density calibration in radio astronomy. The Radio Science Bulletin. 2014, no. 348, pp. 47-66. DOI:

2. De Oliveira-Costa A., Tegmark M., Gaensler B.M., Jonas J., Landecker T.L, Reich P. A model of diffuse galactic radio emission from 10 MHz to 100 GHz. Mon. Not. R. Astron. Soc. 2008, vol. 388. pp. 247-260. DOI:

3. Heald G.H., Pizzo R.F., Orru E., Breton R.P., et al. The LOFAR Multifrequency Snapshot Sky Survey (MSSS). I. Survey description and first results. Astron. Astrophys. 2015, vol. 582, pp. A123, 1-22. DOI:

4. Kundu M.R., Gergely T.E., Erickson W.C. Observations of the quiet Sun at meter and decameter wavelengths. Solar Physics. 1977, vol. 53, pp. 489-496. DOI:

5. Lebedev V.P., Medvedev A.V., Kushnarev D.S. Method to calibrate antenna pattern of Irkutsk IS radar. Trudy IX konferentsii molodykh uchenykh «Fizicheskie processy v kosmose i okolozemnoi srede» [Proc. of IX Young Scientists Conference “Physical Processes in Cosmos and Near Earth Space”]. Irkutsk, 2006, pp. 185-188. (In Russian).

6. Leblanc Y., Le Squeren A.M. Dimensions, temperature and electron density of the quiet corona. Their variations during the solar cycle. Astronomy & Astrophysics. 1969, vol. 1, pp. 239-248.

7. Medvedev A.V., Zavorin A.V., Lebedev V.P., Lubyshev B.I., Nosov V.E. Incoherent scatter radar directional pattern using radio astronomical observations. Eighth International Symposium on Atmospheric and Ocean Optics: Atmospheric Physics. Proc. SPIE 4678. Irkutsk, 2002. DOI:

8. Potekhin A.P., Medvedev A.V., Zavorin A.V., Kushnarev D.S., Lebedev V.P, Lepetaev V.V., Shpynev B.G. Recording and control digital sys-tems of the Irkutsk Incoherent Scatter Radar. Geomagnetism and Aeronomy. 2009, vol. 49. no. 7, pp. 1011-1021. DOI:

9. Setov A.G., Medvedev A.V., Lebedev V.P., Kushnarev D.S., Alsatkin S.S., Tashlykov V.P. Calibration methods for absolute measurements at the Irkutsk Incoherent Scatter Radar. 23rd International Symposium on Atmospheric and Ocean Optics: Atmospheric Physics. Proc. SPIE 10466. Irkutsk, 2017. DOI:

10. Vasilyev R.V., Kushnarev D.S., Kashapova L.K., Lebedev V.P., Medvedev A.V., Nevedimov N.I., Ratovsky K.G. First results of radio observations of the Sun and powerful discrete sources at Irkutsk Radar. Astronomicheskii zhurnal [Astronomical journal], 2013, vol. 90, no. 11, pp. 948-958. (In Russian). DOI:

11. Vasilyev R.V., Globa M.V., Kushnarev D.S., Lebedev V.P., Medvedev A.V., Ratovsky K.G. Model of discrete cosmic radiosource signal for Irkutsk Incoherent Scatter Radar. XXV Vse-rossiiskaya otkrytaya konferentsiya «Rasprostranenie radiovoln» [XXV All-Russian Open Conference “Propagation of Radio Waves”]. Tomsk, 2016, vol. 3, pp. 122-125. (In Russian).

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